How severe is CVE-2021-28311?

CVE-2021-28311 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-28311 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28311?

CVE-2021-28311 primarily affects Microsoft Windows 10. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-28311?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-28311 published?

CVE-2021-28311 was published on 2021-04-13 and last updated on 2026-06-17.

CVE-2021-28311

CVE-2021-28311 is a medium-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Windows 10
Published: 2021-04-13
Last modified: 2026-06-17

Description

Windows Application Compatibility Cache Denial of Service Vulnerability

Frequently asked questions

What is CVE-2021-28311?: Windows Application Compatibility Cache Denial of Service Vulnerability
How severe is CVE-2021-28311?: CVE-2021-28311 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-28311 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28311?: CVE-2021-28311 primarily affects Microsoft Windows 10. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-28311?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-28311 published?: CVE-2021-28311 was published on 2021-04-13 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28311

Affected products (11)

cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Windows 10

CVE-2020-1467 — Critical (CVSS 10.0): An elevation of privilege vulnerability exists when Windows improperly handles hard links. An attacker who successfully…
CVE-2021-26424 — Critical (CVSS 9.9): Windows TCP/IP Remote Code Execution Vulnerability
CVE-2021-28476 — Critical (CVSS 9.9): Windows Hyper-V Remote Code Execution Vulnerability
CVE-2021-26867 — Critical (CVSS 9.9): Windows Hyper-V Remote Code Execution Vulnerability
CVE-2020-1112 — Critical (CVSS 9.9): An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) IIS…
CVE-2019-1384 — Critical (CVSS 9.9): A security feature bypass vulnerability exists where a NETLOGON message is able to obtain the session key and sign…

All CVEs affecting Microsoft Windows 10 →